274 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



The Mt. St. Helena Inn is a little over seven miles from 

 Calistoga on the toll road to Middletown (Lake Co.), just over 

 the top of the pass at the southeasterly end of the southernmost 

 peak of the mountain itself, which rises abruptly from the long 

 ridge extending several miles to the southeast and constituting 

 the easterly wall of Napa Valley. The altitude of the pass is 

 2300 feet. Mt. St. Helena is the most southerly of the higher 

 mountains of the inner Coast Range north of San Francisco 

 Bay, with an altitude given variously on different maps, the 

 greatest of which is 4337 feet for the highest of its three peaks. 

 Its upper slopes are for the most part covered with rocks and 

 brush, with forest extending up the sheltered ravines in some 

 places nearly to the top. The brush is principally scrub oak, 

 chamisal, and manzanita, with some ceanothus. 



Near the top are found a few of the trees and plants of the 

 Sierran association, such as yellow pine {Pimis ponderosa), 

 sugar pine (Pinus lambertiana) and mahala mat, or squaw 

 grass (Ceanothus prostratus). The character of the valleys 

 on each side of most of these inner Coast Range mountains is 

 Upper Sonoran, but the higher peaks of the long ridges still 

 find enough moisture in the breezes from the sea to lift them 

 and their northern slopes from their surroundings and enable 

 them to form an island of Transition, Mt. St. Helena and its 

 immediate vicinity being the southernmost part of this island. 



On the northerly side of the mountain, and on the nearby 

 ranges, the slopes are very steep and heavily covered with 

 forest or brush, even down to a comparatively low altitude, and 

 grassy or arable spots are few and far between for many miles, 

 as are human habitations. 



Dr. Walter K. Fisher spent something over two weeks in this 

 place in 1900 (Aug. 29 to Sept. 14), the result of his observa- 

 tions appearing in The Condor, Vol. II, 1900, p. 135, wherein 

 he gives a detailed list of the arboreal flora and the avifauna of 

 this region. To quote from this paper : 



"Some of the forms on Mt. St. Helena are characteristic 

 of the drier inland districts, while nearly related races are 

 found in the humid coast belt j ust to the west. . . . Thus 

 we have closely related but ordinarily rather widely sep- 

 arated races brought close together." 



